2. Extending phpmailer

Extending classes with inheritance is one of the most
powerful features of object-oriented
programming. It allows you to make changes to the
original class for your
own personal use without hacking the original
classes. Plus, it is very
easy to do. I've provided an example:

Here's a class that extends the phpmailer class and sets the defaults
for the particular site:
PHP include file: mail.inc.php